how to diagnose a Tesla Model S Original (2012-2020) with P0420 code

Learn how to diagnose and fix P0420 exhaust system issue in Tesla Model S (2012-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical issues.

2. Inspect and Replace Oxygen Sensors

1. Locate Oxygen Sensors: Identify the upstream and downstream oxygen sensors near the catalytic converter.
2. Disconnect Sensors: Use a socket wrench to gently disconnect the electrical connectors from both sensors.
3. Remove Sensors: Use an oxygen sensor socket to unscrew and remove the sensors from the exhaust system.
4. Install New Sensors: Apply anti-seize compound to the threads of the new sensors and install them in the correct order.
5. Reconnect Sensors: Reattach the electrical connectors securely to both sensors.

3. Check and Replace Catalytic Converter (if necessary)

1. Inspect the Catalytic Converter: Check for physical damage or signs of clogging.
2. Remove Exhaust Components: If replacement is needed, detach any bolts or clamps holding the exhaust system in place using a socket set.
3. Remove Catalytic Converter: Carefully take out the old catalytic converter from the exhaust system.
4. Install New Catalytic Converter: Position the new catalytic converter and secure it using the original bolts or new gaskets if necessary.
5. Reassemble Exhaust: Reattach any removed exhaust components and ensure they are properly secured.

4. Reconnect Battery and Clear Codes

1. Reconnect Battery: Reattach the negative battery terminal.
2. Clear Codes: Use the OBD-II scanner to clear the P0420 code from the vehicle’s computer.
3. Test Drive: Take the vehicle for a test drive to ensure the check engine light does not return.